472 University of California Publications in Geology [Vol. 8 



the lateral tooth and the anterior dorsal edge suggests that there was 

 a lateral on the left valve which fitted in between the two. 



Dimensions. — Length of shell, 28 mm.; height of shell, 29 mm. 



Occurrence. — In the Upper San Pablo Group to the southeast of 

 the town of Walnut Creek, University of California locality 1478. 

 Only one specimen of the right valve of this species has so far been 

 found. 



TELLINA ENGLISH!, n. sp. 

 Plate 61, figures 6 and 7 



Shell elongate-subovate, compressed, inequilateral, rostrate pos- 

 teriorly. Beaks inconspicuous, posterior to the center with a narrow, 

 dec]) lunule. Eight valve flatter than left and flexed near the 

 posterior end. Anterior end evenly rounded , anterior dorsal edge 

 straight, and nearly parallel with the ventral edge; posterior dorsal 

 edge straight, sloping more steeply from the beak than anterior dorsal 

 edge ; ventral edge long, very gently arcuate except at point of flexure, 

 where it is slightly incurved. Posterior to the flexure on the surface 

 there is a prominent raised ridge which extends obliquely from the 

 beak to the posterior extremity and parallel to the posterior dorsal 

 edge; beyond this ridge and parallel with it, is a well-defined groove. 

 Left valve sculptured by finer concentric lines than right valve, and 

 corresponding to the posterior ridge seen on the right valve there is 

 a groove situated very close to and parallel with the posterior dorsal 

 edge ; there is no well-defined line in front of this groove. 



Tellina englislvi resembles closely Tellina idae Dall, a Recent species 

 on the West Coast. The former differs from the latter in the follow- 

 ing respects: the anterior dorsal edge is straighter and longer; the 

 beaks are more posterior; the shell is longer in proportion to the 

 height, and the ventral edge is less arcuate. Tellina englishi is also 

 very close in resemblance to Tellina tenuistriata Davis, a species de- 

 scribed by C. H. Davis (Jour, of Geol. vol. 21, no. 5, p. 457, fig. 7). 

 The writer has seen some very good specimens in the California 

 Academy of Sciences in San Francisco, which are without doubt refer- 

 able to this latter form. This species though resembling the San 

 Pablo form is easily distinguishable from it. The posterior end of 

 the lower Miocene form is apparently more attenuate ; the posterior 

 dorsal slope is not so steep ; the ventral edge is more arcuate and the 

 shell is higher in proportion to the length. 



